One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,4)(5,6)(7,10)(8,9)(11,12)(21,22,26,32)(23,30,34,36)(24,29,27,31)(25,28,33,35)(6,9)(10,12)(13,14,16,18)(15,19,20,17)(21,23,24,25,26,34,27,33)(22,28,31,30,32,35,29,36)(2,4)(13,15,16,20)(14,17,18,19)(21,24,26,27)(22,29,32,31)(23,33,34,25)(28,30,35,36)(5,7,8,11)(6,10,9,12)(21,25,24,34,26,33,27,23)(22,30,31,35,32,36,29,28)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.